The overall goal is to train the applicant in the methods of social epidemiology to enable him to carry out state-of-the-art research in mental health services and homelessness prevention. As a branch of epidemiology that studies social determinants of health, the candidate will (1) learn epidemiological methods and statistical techniques needed to study social risk and protective factors that are associated with the risk of homelessness among persons with severe and persistent mental illness and the course and outcome of mental illness among chronically homeless persons. Specifically, the candidate will (2) study how different types of social experiences such as social exclusion, social inequality and social support can impact and alter exposure, resistance, persistence, susceptibility and outcome of mental illness in homeless populations. As a part of this research training plan, the candidate will work at the Center for Homeless Prevention Studies (CHPS) of Columbia University's Mailman School of Public Health, an NIMH-funded advanced center for intervention and services research. Under the guidance of Dr. Daniel Herman, co- director of the center's principal research core, the candidate will analyze data from a randomized trial testing the efficacy of a Critical Time Intervention (CTI) for men and women with severe mental illnesses designed to prevent recurrent homelessness during the transition from psychiatric hospitalization to community living (CTI in the Transition from Hospital to Community, R01 MH 059716-05). Specifically the candidate will study the relationship between family social support, continuity of mental health services, and housing status. The candidate will (3) work with faculty and mentors to develop manuscripts for publication and data presentations at national meetings. Through this research training fellowship, the applicant will contribute significantly to public health by studying the effectiveness of mental health interventions among chronically homeless individuals suffering from persistent and severe mental illness. Knowledge gained from understanding the interaction between the social environment and individual determinants can be harnessed to enhance the effectiveness of fostering individual recovery and promote a more productive life.